How Long Is a Reticulated Python? The World's Longest Snake

Typical length of adult reticulated pythons

The reticulated python of South and Southeast Asia is the only living snake that regularly grows past 6 m (20 ft). The best large sample comes from southern Sumatra, where researchers measured more than 1,000 wild pythons taken for the skin trade. They ranged from 1.5 to 6.5 m (5 to 21 ft) long and weighed 1 to 75 kg (2 to 165 lb).

Females are the giants. They grow longer than males and become much heavier, so almost every record-breaking python is a female. Growth is fast when food is plentiful: a young python can more than quadruple its hatching length within its first few years, and it keeps growing, more slowly, throughout its life.

The longest reticulated pythons on record

The longest scientifically measured wild specimen came from Balikpapan in East Kalimantan, Indonesian Borneo. It was measured under anesthesia at 6.95 m (22 ft 10 in) while vets removed a radio collar it had swallowed along with a sun bear. Even after nearly three months without food, it weighed 59 kg (130 lb).

The longest snake ever kept in captivity, according to Guinness World Records, is Medusa, a female reticulated python in Kansas City, Missouri. In 2011 she was measured at 7.67 m (25 ft 2 in) and weighed 158.8 kg (350 lb). Another captive female, an albino named Twinkie in California, was recorded at about 7 m (23 ft).

For comparison, the longest wild Burmese python ever measured was 5.79 m (19 ft), and the longest verified green anacondas reached a little over 6 m (20 ft). See our ranking of the largest snakes for the other giants.

Why so many length records are exaggerated

Few animal records are as inflated as giant snake lengths. There are several reasons:

• A live python cannot be stretched straight. A big snake is enormously strong and resists being handled, so measurements of live animals are often estimates built from several partial measurements.
• Skins stretch. When a snake is skinned and the hide is dried or tanned, it can become 20 to 40 percent longer than the snake was in life, so a hide is not proof of length.
• People overestimate. Seen in the wild, half-hidden in vegetation or water, a big snake tends to look much longer than it really is.

A famous example is Colossus, a male reticulated python kept at the Highland Park Zoo in Pittsburgh in the 1950s and early 1960s. Its length was once reported as 8.7 m (28 ft 7 in). After it died in 1964, its skeleton measured 6.35 m (20 ft 10 in) and its fresh hide 7.29 m (23 ft 11 in), and a 2012 review concluded that it was neither the longest nor the heaviest snake ever kept. More recently, an Indonesian python advertised as 14.85 m (48 ft 9 in) turned out to be only about 6.5 to 7 m (21 to 23 ft).

For decades the New York Zoological Society, now the Wildlife Conservation Society, offered a reward, eventually raised to 50,000 US dollars, for a live, healthy snake of 30 ft (9.14 m) or more. It was never claimed. Scientists accept only measurements made on dead or anesthetized snakes, ideally preserved in a museum.

Dwarf reticulated pythons on small islands

Not all reticulated pythons are giants. On some small islands in the Selayar Archipelago south of Sulawesi, pythons stay much smaller, probably because large prey is scarce. The Tanahjampea form rarely grows much beyond about 2 m (6.5 ft), and the Selayar form is not known to exceed about 4 m (13 ft). These populations have been described as separate subspecies, although not all authorities recognize them.

Dwarf pythons follow a pattern common on islands, where big animals often evolve to be smaller and small animals larger. Their small size shows that a reticulated python’s final length depends on food as well as on its genes.

How length relates to weight

Length and weight do not rise together in a simple way. Because a snake’s girth grows as it gets longer, weight climbs much faster than length: a 6 m (20 ft) python may weigh several times as much as a 4 m (13 ft) one. Weight also changes greatly with recent meals, pregnancy and condition.

Wild reticulated pythons are relatively slender, which is why the record 6.95 m snake weighed only 59 kg (130 lb). Well-fed captive snakes can become far heavier, as Medusa’s 158.8 kg (350 lb) shows. This slimness is also why the green anaconda, although shorter, is the heavier species; compare their sizes in how big is a green anaconda?